Mid-term clinical and radiological changes of ankle joint in knee osteoarthritis with varus after total knee replacement

Purpose: In varus knee osteoarthritis patients, compensatory changes occur in the foot and ankle joints to compensate for the knee varus. The aim of the study is to investigate the changes in the ankle of patients whose knee alignment was corrected with TDP and their clinical reflections. Materials and Methods: From 2019-2022, 402 patients with knee osteoarthritis underwent primary, cemented, posterior stabilized total knee arthroplasty at Ankara City Hospital. 179 patients, 204 extremities were included. Demographic data of the patients, body mass index (BMI), follow-up period and X-rays were examined. The hip-knee-ankle angle (HKA), knee joint line convergence angle (JLCA), talar tilt angle (TT), ground talar dome angle (GT) and ground tibia plafond angle (GP) were evaluated with full-leg standing anteroposterior radiographs taken at preoperative and last follow-up. The American Orthopaedic Foot and Ankle Society (AOFAS) Score, which was filled in at the preoperative and final controls, was evaluated. Results: 204 knees of 179 patients with a mean follow-up of 30.50±6.68 months were evaluated. It was found that the change in HKA had a positive effect on the AOFAS score and a negative effect on the TT, GT and GP angles. While clinical score improved in 82 patients, clinical score worsened in 8 patients. The age difference between the group whose AOFAS score improved and worsened was statistically significant. There was no significant difference between the two groups in terms of gender and BMI. A significant difference was found between the preoperative TT values of the patients whose AOFAS score improved and worsened. It was found that patients with worsening AOFAS scores had less change in TT and GT angles than patients who improved. Conclusion: When varus malalignment in the knee was corrected, it was shown that compensatory valgus that developed in the foot and ankle also improved in the mid-term, and a statistically significant improvement was observed in the ankle clinical score of the patients. Keywords: Arthroplasty, Ankle Joint, Genu Varum, Knee Osteoarthritis, Total Knee Replacement